Mycoplasma hyopneumoniae (Mh) is the etiologic agent of swine enzootic pneumonia. It is one of the most important diseases that affect swine and usually causes the most important loss of animals. The disease generally results in inefficient weight gains and in sickly animals. Mh-infected swine are also subject to secondary infections, eventually leading to death.
Different vaccines for protecting swine against Mycoplasma hyopneumoniae infections have been reported. These include, e.g., vaccines comprising surface antigens of Mh (EP283840), a vaccine comprising plasma membranes of Mh, or vaccines comprising live or inactivated Mh bacteria (U.S. Pat. No. 3,917,819, WO2009/61798). The above vaccines, however, do not always provide satisfactory protection in vaccinated swine. In particular, these vaccines do not appear to generate appropriate cellular and humoral responses to cause efficient protection of animals.
Vaccines comprising inactivated Mh strains are also commercially available, such as Respifend®. This vaccine requires several injections.
There is a need for improved compositions inducing better immunogenic responses in animals, to confer stronger protection against diseases caused by pathogenic agents such as Mh.